Celica GT4 Forge Engine Build, Upgrade Options

[cloqwise]

Right this is going to be pic heavy but I have been building my car for a good while now and its pretty much finished. Done 2 threads on the TOC and gt4oc.net and i know most people on here are americans so i thought this would make a good source of info as you guys didn't get the st205 over there officially.

This is basically how the engine looked before i started stripping it, unfortunately the car club nazi's on my military base have taken up all the room in the garages I had to do this outside over late summer and through the winter. I'm sure people know about the UK weather so its not the best way to do this as i got frozen many a time.

Now as you can see the intercooler route isnt the best and basically the more i stripped the engine the more i learned and i would consider myself quite a knowledgable bloke on engines now cause i cannot stress how much you learn from doing this from rebuilding, general maintenance and modifying.





As you can by the big gap at the front i took the turbo off in a oner including the exhaust manifold, comes off really easy altogether was quite surprised. As you can see the exhaust valves are nicely scorched and gave me the idea of replacing all valves and doing a little more head work than planned. After i took the head off i took it to get skimmed and a bit of a clean up, this is what they found while skimming it, basically these are either det marks or where a piston ring exploded. Luckily as you can see on the picture all marks fit inside the gasket bracelet making the head still serviceable to use. Basically i have had 2 blocks before this so some parts have migrated over to this engine, back then i didnt do much on the car myself so whether i had cowboys working on the past engines who knows. My other two engines basically what happened was, crashed my car and cracked the block so rebuilt the car, finally discovered the block was knackered after elimnating everything else and got a new one in. After a few thousand miles i was having minor temperature problems with the new block so enough was enough, plus my last few gfs pissed me off enough to decide screw women for a while my car needs me more. You will see the problem i found later on but for now the head was skimmed by 0.005"









For uprating the head i decided on getting ferrea valves, titanium retainers, new collets, new buckets with 8mm shim, dual springs, HKS 264 camshafts and some vernier pulleys. 272 camshafts would have put the power band way up the rev range and would require extra machining on the valve train. The dual springs are proper nails, just so much stiffer.
New setup


Old setup

and where the engines at for the time being

Plus Suspension and driveshafts need disconnecting

Underneathe the car, prop shaft disconnected

Cross member needs to come out

Must apologise for the lack of action shots, this is my first strip and build, did it mostly on my own and was really focussed when i was set about the engine.

Right now for the fault with the engine, once i pulled the engine out the car i removed the pistons and this is what i found

A horizontal crack, quite rare as usually they are vertical and with a bit more blackening around it. Unfortunately this meant new block but someone off the gt4oc.net sourced one for me and she was in much better condition than my current block so was very happy.





After pulling the pistons, i did actually think to myself wouldn't it be great if they were some gucci racing pistons and this is what i found



Oh yes CP 86.5mm pistons, quids in boyos

Will start a second post cause this is going to be super long.

[cloqwise]

Really must apologise here, no action shots of putting it in, was only two of us and time was against us. So bit of a jump but, the engine went in, some tips to doing it is makes sure the radiator is out, the turbo system being off makes so much more room, leave the alternator off and the thermostat housing. Remember when you put the worm drive on the transfer box, basically the device that translates the drive into the prop shaft make sure you put this on while the engine is like 3/4's in otherwise you won't be able to tighten up all the bolts.

So the engine is in





At this point in timing there was a lot of waiting around for turbo parts, plus i decided to try a tubular manifold off ebay and see if i could rig up some struts to take the weight and stop it from cracking. However once i got the manifold, basically it was **** so i sent it straight back and turned my attention to the cast iron manifold. The cast iron manifold is a great bit of kit although heavy its a strong old thing and will around max around 500bhp. Some fettling was required though as my garrett is a single engtry turbo and the standard turbo is twin entry so i needed to take the bridge out of the manifold. You can do this by grinding it which takes ages and i gave up after 37minutes, came to my senses and took it to the machinist. They took it down to a knife edge for me but do not leave it like this whatever you do, the knife edge will be hit by exhaust on more than one side and i was told will probably melt at 1000deg and go down my turbine. All you need to do is getting something like a dynafile and flatten the edge out so its nice and blunt. To helpt the engine breathe porting and polishing down the runs of the exhaust manifold with a flexi shaft is a must, opening them out will help quite a bit.


Like i said do not leave it knife edged!


Then ceramic coated it using some stuff called cermakrome from demontweeks which isnt too expensive but has had good write ups, anything to keep the heat from radiating.

I got this idea off my mate for the water injection nozzle (by the way never get your car mapped with water injection, put it on afterwards. If its mapped with it and the water injection fails, engine will go bang), the gt4 throttle inlet is this rubber thing, the mr2 turbo rev3 onwards has a solid inlet which you can fit to the gt4 and this is where i will drill and tap the inlet for the wi nozzle.



The car was coming along nicely now, as you see in these 2 pictures my additional oil cooler (blue one) for the engine. This is a must on any gt4 as the normal oil cooler just cannot cut it and standard cars see oil temps of 100deg's at crusing speeds. The other is a bigger gearbox oil cooler with the power steering cooler removed, you don't really need one unless on track and its not hard to setup.



By now my header tank had turned up, something the gt4 does not have and will help massively in reducing temperatures. Always use one in conjunction with a swirl pot which will help take air bubbles out of your coolant system something that you do not want. The header tank must always be higher than the top of the radiator so the suspension tower is always a good place to mount it. I made up some crude brackets (i'm not going for presentation by the way) and awaited the arrival of my swirl pot. Now that i remember, the standard over flow bottle is no longer needed so get rid of that, get rid of the rubber seal off the bottom of the rad cap aswell. The 3 ports on the header tank are for rad overflow to header tank, swirl port to header tank, and the big one is the drain from the header tank. You will need an alloy T piece plummed into your cool system so the tank can drain into it, best place is the bottom rad hose just as it comes out the radiator.








My turbo parts now in my possesion i hooked the turbo up, the turbo inlet needs to be pointing directly on top of the turbo and the oil drain needs to be made sure its point downwards otherwise oil will build up in the turbo and you may blow the seals, this is why garretts need a restrictor piece for the oil turbo feed. Unfortunately i had to use an adapter piece which is what the blue wastegate is attached to, the wastegate was resting on the standard oil cooler in this position so i bought a relocation pipe to fix this. The oil drain i just made up of silicone pipes, bends and alloy couplers, a lot of people go for gucci braided hoses but i am mr cheap when it comes to this as i got a lot of my parts so much cheaper by shopping around and prowling ebay. I got my conrods for 180 quid and my brand new garrett was 600 odd quid when they go for 1500 usually.